Coalescers are employed for separation of liquid to liquid suspension. Examples include the coalescing of water out of petroleum based products or the coalescing of petroleum based products out of water. Coalescers can be used for separating a variety of liquids from liquids, such as removing suspended hydrocarbon or oils from water, such as from tank farms, petroleum marketing facilities, refineries, utilities, gasoline stations, vehicle repair and maintenance shops, petrochemical plants, truck stops, parking lots, steel mills, storm water run off, surface run off, street wash waters, and the like. Various state and federal acts and regulations prohibit the discharge of any pollutants to United States navigable waters, pollution from natural storm water run off as well as illicit disposal in the storm sewers. Under current storm water regulations, drainage systems must be capable of removing contaminants, such as the petroleum hydrocarbons, from storm water run off at least down to 15 parts per million concentrations, which includes the removal of all free petroleum droplets equal to or greater than 20 microns in size.
Conventional methods of separating liquid droplets entrained in liquids, such as oil in water, include gravity separation, filtration, absorption, cohesion disposition, air floatation, microbiological, electrolytic, physical, chemical, and coalescing methods.
The following patents are illustrative of the state of the art developed in a preliminary search.
U.S. Pat. No. 2,651,414 illustrates a hydrocarbon separator apparatus which utilizes a cylindrical wall freely perforated or of expanded metal permitting relative free flow of liquid through it for separation.
U.S. Pat. No. 3,830,371 illustrates a liquid to liquid separator by passing through confined particle material which has an affinity for one of the liquids.
U.S. Pat. No. 4,231,867 discloses a method and apparatus for separating heterogenous fluids by flowing a gas through a liquid phase in a plurality of substantially vertical conduit members over a manifold member through which the gas is supplied, the gas carrying the liquid bubbles to the surface and circulating downwardly on the outside of the tubes.
U.S. Pat. No. 4,299,699 illustrates a back washable helical-media coalescer, the coalescer media composed of yarn-like material.
U.S. Pat. No. 4,479,875 illustrates an inlet distributor for a liquid-liquid separator including a distributor mounted within the separation zone provided with fluid openings having packing means disposed thereabout.
U.S. Pat. No. 4,919,777 discloses an electrostatic mechanical emulsion treating method and apparatus which includes an electrically grounded coalescing element comprising a multiplicity of longitudinally-extending downwardly inclined open ended tubes arranged in bundle fashion.
U.S. Pat. No. 5,028,323 discloses a filter for corrosive liquids which includes filter tubes formed from commercially available plastic tubes having multiple openings to provide for liquid passing between the inner and outer areas of the tubes.
U.S. Pat. No. 4,591,441 discloses a method and an apparatus for separating oil from water in which an oil water separating element consisting of specific porous material is used which includes a water insoluble hydrogel layer formed on the porous material surface and/or the surface of a fluid passage to be contacted with oil holding water.
U.S. Pat. Nos. 4,359,329 and 4,722,800 disclose separators provided with deflecting baffles and manways to provide access to the separator tank.
Commercial coalescers available on the market utilize mesh and plates to cause lighter oils to rise and coalesce into larger droplets which collect on the mesh or plates until they are large enough to break away and rise to the surface.
None of the foregoing patents or liquid to liquid coalescers available at present disclose, suggest, or use a liquid to liquid separator utilizing one or more upright or vertical coalescer tube assemblies of oleophilic, fiberglass composite or metallic materials having its side walls perforated so that the liquid flows into the tubes, small droplets of liquid coalesce on the inner walls of the tubes and increase in size until they break away thereby increasing the rate of rise of the droplets within the tubes, and liquid free of the coalesced droplets flows out of the tubes by which highly advantageous results are obtained.